Conventionally, a bicycle includes a pair of wheels, one chain, a pair of pedals, and a handle that allows a passenger to steer the front wheel. The pair of wheels are mounted with a driving sprocket and a driven sprocket, respectively, and are connected to each other via a chain.
Thus, when the passenger steps on the pedals with two feet to rotate the pedals in the advancing direction of the bicycle, the rear wheel connected to the chain is adapted to advance in the advancing direction of the bicycle by a force applied via the rotated pedals.
However, the conventional bicycle is provided with a power transmission apparatus for transmitting a power (e.g., a pair of sprockets and a chain that interconnects the sprockets), and the pedals shall always be rotated forward in order to ride the bicycle.
In this regard, Korean Laid-Open Patent Application No. 10-2011-0039179 discloses a bicycle that is equipped with a power transmission apparatus configured to output a rotation power in the same direction regardless whether pedals are rotated either in the forward direction or in the reverse direction.
In order to output the rotation power in the same direction regardless of the rotating direction of the pedals as disclosed, the bicycle includes a power transmission apparatus that is operated when the pedals are rotated forward, and a power transmission apparatus that is operated when the pedals are rotated reversely.
That is, a pair of power transmission apparatuses are provided in which a chain of one of the power transmission apparatus is wrapped in an open type, and a chain of the other power transmission apparatus is wrapped in a cross type such that when the pedals are rotated in the advancing direction of the bicycle, the one power transmission apparatus is operated to make the bicycle travel forward, and when the pedals are rotated in the reversing direction of the bicycle, the other power transmission apparatus is operated to make the bicycle travel forward.
However, the power transmission apparatuses applied to the bicycle have a problem in that since it is necessary to interpose a one-way clutch in order to keep a power transmission apparatus in the neutral state while the bicycle is traveling, the overall structures and sizes of the power transmission apparatuses are complicated and enlarged.